Improvement in safety-devices for elevators



U PIP. LANE. Improvement in-SafetyDeVice for ElevatorsJ N0. 128,152,PatentedJune18,1872.'

INVE'NTOR My/WQIZV UNITED STATES PATENT QFFICE.

PHILANDER r. LANE, on omomnA'TI, onro, ASSIGNOR TO LANE &

' BODLEY, or SAME rLAoE.

IMPROVEMENT IN SAFETY-DEVICES FOR ELEVATORS.

Specification forming part of Letters Patent No. 128,152, dated June 18,1872.

I, PHILANDER P. LANE, of Cincinnati, Hamilton county, Ohio, haveinvented a new and useful Safety Device for Power Elevators, of whichthe following is a specification:

My invention is designed for the class of power elevators or hoists,whose movable platform is suspended from the operating-cable. Elevatorsof this kind are commonly provided with a safety device, so called,which device consists essentially of one or more pawls, intended,whenever the cable breaks or gives way from any cause, to engage withstationary racks, with which the guide-bars are armed throughout theirlengths, such engagement bein g supposed to be secured by springs,intended to become effective on the interruption of the cable-tension.This expedienthasproved entirely unreliable, the springs, beingmaintained at full tension, and performing no service so long as thecable continues intactwhich may be months or yearseither lose theirresilient power, or become sprung or broken, or so brittle as to snap atthe critical moment, or the pawls encountering the tops instead of theinterstices of the rack-teeth, and failing to promptly arrest thedescent of the platform, are swiftly swept by the momentum of thedescending mass so rapidly from tooth to tooth as to afford no time forengagement; or, if at last entering, are either broken by or break theteeth of the racks 5 indeed, immediate effectiveness is vital to suchapparatus, because if the platform once acquired the momentum of even abrief unopposed descent it is practicably irresistible.

The above-stated defects I avoid by the use of eccentric clamps, which,at the instant of impact, co-act with jaws to firmly grasp guidebars,smooth throughout their lengths, the said clamp-action being broughtinto play by the descent of a reversely-acting counter-weight,

, connected to the levers by a suitable chain or cable, as hereinafterfully explained.

In the accompanying drawing, Figure 1 is a side elevation of a platformand accessories embodying my invention, the parts being in their usualposition. Fig. 2 is a vertical section, on a larger scale, showing theself-clamping devices in action after the snapping of the main cable.Fig. 3 is a horizontal section at the line a m, Fig. 2. Figs. 4 and 5are, re-

spectively, enlarged views of the clamping delengths, is a box orhousing, D, for the slid-- ing block E, to which the main cable F issecured. All of the above parts are old and well known. The block E hasa horizontal slot, G, to receive two levers, H H, connected by links I Iand rocker J, with a chain or wire-cable, K, which, being carried overtwo pulleys, L L, situated somewhat higher than the highest hatchway,suspends at its other extremity my reversely-acting counter-weight. M.Each lever H H terminates in a circular or other suitable cam oreccentric, N, which is, by means of a pivot-bolt, O, journaledeccentrically in cheek-plates 1?, whose lower ends are pivoted at Q tothe posts B or B. Each cheek-plate terminates in a lug, p, which, beingconnected by brace-rod R with the floor or other suita-.

ble part of the platform, relieves the pivot Q from the principalportion of the strain incident to the arrest of the descending platform.The guide-bars or stanchions S S are preferably of wroughtiron, havingthe represented l-shaped transverse section, and being entirely smoothand parallel-sided throughout their length. Flanges s s, which projectlaterally from said bars, serve to give proper stifi'ness to and topreserve the reotilinearity of saidbars, and serve as guides or ways forflanged roll ers T T and U U, which hold the platform in position. Theseflanges, in my invention, are further useful in conjunction with thegriping devices, hereinafter described, to arrest a descending platform.V V are bars, which extend horizontally from bolt 0, through notches win brackets W, and are furnished at their other extremities with jaws XX, which, when the eccentric is brought into service, are caused topress against the rear sides of the flanges S S, and to co-operate withsaid eccentrics in firmly and instantly grasping the guide-bar. Theeccentric N may either have smooth peripheries and bear directly againstthe inner faces of the guide-bars, or may bear against sliding-racks Y,which are supported in position by reason of their teeth y, occupyingcorresponding indentations a in the eccentric peripheries.

The operation of the above-described safety attachment is as follows:The instant that the tension of the main cable is interrupted from anycause-as for example, by becoming broken, as in Fig. 2, thecounter-weight and the descending platform co-act to depress the levers,and thus bring the more divergent portions of the eccentrics to bear inthe slidingracks, and through them on the faces of the the guide-bars,and the same movement operates through the pivot O and the bar V V, tobring the jaws X X in close contact with the rear sides of flanges S S,so as to grip the guide-bar tightly between the opposing surfaces of thesaid jaws and racks y with a force proportional to the descending stressof the platform and its opposing counter -weight, thus holding theplatform instantly and firmly against any further descent.

It will be seen that the descending counterweight, with the upward pullof its cable on the one hand and the descending platform on the otherhand, act in direct opposition to each other, and thus throw theeccentric clamps into contact with the guide-bars with a force due tothe sum of the opposing actions of the platform downward, and thecounter-weight cable upward; and that the clamps, consequently, take afirm hold almost at the precise spot where they first strike theguide-bars, and thus by preventing any appreciable descent, prevent,also, any serious accumulation of momentum.

The jaws X X, co-acting with the eccentries to grip the guide-bars, nodanger arises of the apparatus becoming non-effective by reason oflateral deflection or lack of rectilinearity of the guide-bars.

The extended surfaces of the sliding racks Y, in contact with theguide-bars, secure at once the necessary adhesion. The peripheries ofthe eccentrics simply rolling on the racks,

are effectually protected thereby, and are not liable to be ground OK asthey would be by direct contact with the said bars.

The counter-.weight cable being constantly in plain view, the user ofthe elevator can always assure himself of the efficiency of the safetymechanism, the construction and mode of operation of which is also anassurance of effective action.

The described guide -bars or stanchions, smooth and parallel throughouttheir length, and with the represented l-section, are well adapted forthe explained co-action with my described clamping-jaws, and arebelieved to be entirely new and highly valuable in such connection.

If desired the two flanges of the said guidebars most distant from theplatform may be omitted, so as to give the guide-bar a T-formed insteadof an l-formed section.

I do not claim, broadly, the use of eccentric levers and counter-weight,such being old, as applied to safety devices of this kind; but

What I do claim is- 1. The j aws X X, which co-act with the camlevers togripe the flanges of the guide-bars, so as not to depend upon theabsolute rectilinear ity and inflexibility of the bars.

2. The sliding wedge or rack Y, interposed between the cam and the bar,to protect the periphery of the cam, and secure adequate impingingsurface.

3. The indented eccentric N n, levers H H, rocking-lever J, arms I I,and jaws X X, in combination with the cage 0, rack Y, guidebars S S, andcounter-weight M, all constructed, arranged, and operated as set forth.

4. T or l-shaped guides,in combination with the clamping-j aws X X, andeccentrics N, substantially as described.

In testimony of which invention I hereunto set my hand.

PHILANDER P. LANE.

Attest:

GEO. H. KNIGHT, JAMES H. LAYMAN.

